Microsoft PsExec

Microsoft's PsExec is a lightweight, yet powerful command-line tool that is part of the Sysinternals Suite. PsExec allows users to execute processes remotely on other systems. It is widely used by system administrators for its ability to execute programs on remote systems without the need to manually install client software on each target machine.

PsExec enables you to run programs on remote systems. You can have the output of these programs displayed on your own system, or run them in the background on the remote system. PsExec operates from the command line, offering a high level of control and scripting capabilities.

You can run commands as the local system account, as the currently logged-on user, or as a different user by providing credentials. PsExec can copy the necessary executables to the remote system to run the command and then remove them afterward. It's commonly used for network administration tasks like updating group policies, deploying software, running scripts, and performing diagnostic tasks across multiple machines.

An example may be:

PsExec \\RemoteMachineName ipconfig /all

PsExec typically requires that you have administrator privileges on the remote machine to execute commands. PsExec communicates over the network, and the traffic is not encrypted by default. In sensitive environments, it's important to consider the potential security implications.

Some ways it can be used offensively include:

  1. Lateral Movement: Once gaining access to one machine in a network, attackers can use PsExec to execute commands or deploy malware on other machines within the network, moving laterally to expand their reach.
  2. Running Malicious Code: Hackers can use PsExec to run malicious scripts or programs on remote systems. This could be used to install backdoors, keyloggers, or other types of malware.
  3. Privilege Escalation: By using PsExec with stolen credentials, attackers can execute commands with elevated privileges, potentially gaining administrative access on remote systems.
  4. Maintaining Persistence: PsExec can be used to install services or applications that allow attackers to maintain access to the network over time.
  5. Evading Detection: Because PsExec is a legitimate Windows tool, its usage might evade detection by some security software, allowing attackers to use it without immediately raising alarms.